The present invention relates to a machine for positioning and leveling plates for electric accumulators, to be arranged within the process for production of the plates themselves.
The machine in question is designed to be used downstream of a machine for separating lead grids and upstream of an annealing furnace prior to stacking and final storage of the plates on pallets.
As is known, the grid separating machine is intended for dividing a continuous strip of plates into pairs of plates separated from one another, by means of the use of two parallel counter-rotating rollers provided with cutters. Upon leaving the separating machine, the plates are divided, curved by the action of the aforementioned rollers, staggered with respect to one another and arranged in a fairly disordered manner. The lack of alignment of the plates upon leaving the machine is an inevitable consequence of the production process which is intended to produce plates with lugs for the electric contacts which, depending on requirements, must be able to be formed in different positions along one side of the plates themselves.
At present, in accordance with the known art, use is made of a positioning and leveling machine having the following: an upstream section, arranged in the vicinity of the separating machine for removing the outgoing plates; a downstream section, arranged in the vicinity of the annealing furnace for charging thereof; and a central section designed to perform conveying and mutual spacing of the plates of each pair of plates.
This machine, which is of a known type, involves the use, in the upstream section, of a first motorized conveyor belt able to convey the plates underneath a compression roller which pushes them against the rigid surface of the conveyor belt, causing leveling thereof.
Advantageously, it also involves the presence of an extraction roller with a small diameter to be inserted into the vicinity of the separating machine outlet in order to remove the plates in the vicinity of the two rollers provided with cutters. The central section of this known machine is associated with two diverging series of belts designed to transfer the pairs of plates from the outlet of the compression roller to the downstream section of the machine, performing at the same time spacing of the individual plates which make up each pair.
In order to connect the conveyor belt to the two series of belts, use may be made of a connecting roller.
The downstream section is provided with conveying means designed to remove the plates from the aforementioned central section and transfer them to the furnace charging hatch. These conveying means may consist of either a second conveyor belt or a series of transfer rollers.
This conveyor design, already known and briefly described above, has numerous drawbacks.
First of all, it involves, for transfer of the plates from the upstream section to the downstream section, the use of different conveying means which cause small displacements of the plates themselves when passing from one conveying means to another. This results in disordered positioning of the plates at the outlet of positioning and leveling machine. In fact, especially during the transfer between one conveyor belt and a belt group, small jumping movements occur and disturb the arrangement of the plates, causing uneven transfer thereof onto the conveyor means which is located downstream. This results in difficulty in stacking the plates during a final collection stage (for example at the annealing furnace outlet), whether a manual collection method is used or automated collection performed.
A first requirement which arises, therefore, during the final collection stage of the production process is that the plates should be adequately ordered and oriented in a suitable manner so as to make quicker and easier, and hence less costly, stacking and storage thereof onto pallets.
As stated above, upon leaving the positioning and leveling machine of the known type, the pairs of plates are spaced and staggered with respect to one another, with the front part not aligned. Moreover, the plates of each pair which emerge from the separating machine have their front part inclined towards the outside of the machine itself. This occurs because the aforementioned two rollers provided with cutters grip the central part of the continuous strip of plates more firmly than the lateral parts.
Another disadvantage of the positioning and separating machine of the known type also consists in the fact that there are no suitable contrivances for ensuring lateral alignment and frontal lining-up of the plates which allows the latter to be positioned, upon leaving the machine itself, in an ordered condition designed to ensure easy collection thereof.
An essential object of the present invention is therefore that of overcoming the drawbacks of the known art, providing a machine for positioning and leveling plates for electric accumulators which allows pairs of plates to be conveyed from its upstream section to its downstream section, causing spacing thereof perpendicular to the direction of feeding, alignment of the front part, rotation in the positional plane and leveling.
Another object of the present invention is that of performing the aforementioned leveling of the plates in the vicinity of the outlet of a separating machine, carrying out gripping thereof before they have emerged completely from the separating machine, in order to prevent the presence of connecting elements between the plates (due to an imperfect cutting operation of the separating machine) from disturbing the correct arrangement of the plates themselves leaving the separating machine.
Another object of the machine in question is that it should be reliable and safe and that the plates should be arranged at its outlet in an ordered condition such that they can be easily collected, envisaging moreover the use of conveying means which are able to transfer the plates without disturbing the arrangement thereof as a result of the jumping movements.